I understand that you had another developer look at things but permalink issues by themselves are not typically a conflict with the theme but a server side issue. Have you tried to delete the htaccess file and let it get regenerated from scratch, disable *all* active plugins (then refresh permalink settings by switching to default, saving and switching back).

I’m not suggesting you permanently switch to default permalinks as post-name is better for SEO in general but in general the portfolio custom post type works so its just a matter of finding the issue on your instance which is causing them not to work.

I just want to follow up on this for everyone to see. I have not been able to get individual portfolios to show up. Always a 404 error. Devin told me to delete all my plugins and put them back on. I only use 21 plug-ins so it wasn’t a big deal. The culprit?

Google Analytics Link Builder broke the portfolio. I use All In One SEO and have had that other plug in for years … so I was surprised! Anyway, wanted to share with others in case it’s happening with you.